As various electronic devices are used in most products such as automobiles and ships that are manufactured in various industrial fields, the status of semiconductor industry is increasingly raised in modern industrial structure. As semiconductor devices are used in various industrial fields and become an important factor affecting the quality of electronic devices, automobiles and ships, demands on semiconductor device having excellent characteristics are being increased. In order to meet such demands, semiconductor technologies are being developed to implement high-integration, low power consumption, and/or high speed of the semiconductor devices.
Since data storage capacity and data recording and deleting characteristics of nonvolatile memory devices among semiconductor devices determine the reliability of various apparatuses equipped with the nonvolatile memory devices, their importance is being increasingly recognized.